Gaseous electric discharge device



@cih 69 36., 4 K BECKER Zg GAsEoUs ELECTRIC DISGHARGEDEVICE Filed Nov. ll, 1932 5 if YSZ Z 5 3657;! j f7 5 g5 if? 2g j@ im if ATTORNEY menaioesse, rese s' y Unire-o sras AT fi GASEOS ELECTRIC DISCHARGE DEVICE Karl Becker, Berlin-Steglitz, Germany, assigner to General Electric Company, a corporation of New York Application November 11, 1932. sei-iai N0. 642,319 In Germany November 25, 1931 v'l Claims.

The present invention relates to gaseous electric discharge devices generally and more particularly the invention relates to such devices in which the gaseous electric discharge is of the concentrated or so-called stringy discharge type similar to those described in co-pending application Serial Number 592,138, flled February l0, 1932, which corresponds to British Patent 377,584, the inventors being Marcello Pirani and Martin Reger.

In the application referred to above the concentrated stringy discharge is guided along the axis of the container of the device by one or more centrally punctured septums which, by guiding the concentrated discharge, keeps said discharge away from the walls of the container and makes it possible to use a softer and more easily workable glass for the container than would otherwise be practical. The object of the present invention is to improve the efiiciency of su ch devices. Another object of the invention 1s to simplify the manufacture of such devices. A further object is to facilitate the starting of such devices. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description and from the appended claims.

I have discovered that half-discs are as eicaclous as the punctured septums described in the application referred to and that said half-discs do not obstruct the light in at least one direction and, when suitably connected to one of the electrodes of the device, also facilitate the starting of the electric discharge between the electrodes of the device and simplify the manufacture of the device.

In the drawing:-

Fig. 1 is a side elevational, partly sectional view of a gaseous electric discharge device embodying my invention,

Fig. 2 is a sectional view along the line 2-2 of mg- 1:

Fig. 3 is a side elevational, partly sectional view of another embodiment of my invention,

Fig. 4 is a. similar view of still another embodiment of my invention,

Fig. 5 is a sectional view along the line 5-5 of Fig. 4, and Fig. 6 is a side elevational, partly sectional view of another embodiment of my invention.4

Like numbers denote like parts in all the yiigures.

Referring to Figs. 1 and 2 of the drawing the new and novel gaseous electric discharge device comprises a container I, having thermionic electrodes 2 sealed therein at each end thereof. Electrode leads 3 of said electrodes 2 are sealed into the pinch parts 4 of stems 5 of said container l. Said electrodes 2 are of the sintered, mixed metal 5 and oxide type made in accordance with` the disclosure of co-pending application, Serial Number 377,044, filed July 9, 1929 being the invention of Marcello Pirani and Hans Ewest, or when desired. anyv other suitable type of thermionic electrode 10 may be used. Each of said electrodes 2 is surrounded by a metal cylinder 9 which is concentric therewith and which has in the direction of the discharge path a flange with an opening II therein. Said opening II is concentric with the l5 longitudinal axis of the containerl. Said cylinders 9 are supported by wires or rods sealed in pinch-parts l of stems 5. Two half-discs Il and I8 are arranged on the same side of container I perpendicular to the discharge path between said electrodes 2 and are at equal distances along the discharge path between said electrodes 2. The inner rims of said half-discs Il and I8 are concentric with the longitudinal axis of said container I and the outer rims thereof are separated from the inner wall of said container l a distance less than the mean free path of an ionized gas\particle. Said discs I1 and I8 consist of a metal, such as molybdenum, and, where desired, are degassed. Said discs are attached to the inner wall of the container by small glass beads I9 and 20. Said container I is lled with an electric discharge conducting gaseous atmosphere such as a mixture of a rare gas, such as neon, and a, metal vapor, such as sodium, mercury, or potassium, 35 the body I2 indicating the vaporizable metallic material. Preferably the gaseous atmosphere consists of argon and mercury vapor. Said gaseous atmosphere is at a pressure higher than when a diffuse electric discharge is desired to ll 40 the container I between said electrodes 2, for example, a pressure higher than 30 millimeters.

When current is applied across the terminals of the device said electrodes 2 are brought to an electron emitting temperature by an initial gas 45 glow discharge which rapidly changes into the desired mercury vapor arc discharge, or when desired said electrodes are brought to such temperature by a heating ilament adapted for that purpose. Due to the high pressure of the gaseous 50 atmosphere the discharge between said electrodes 2 is of the concentrated, stringy type and said discharge is guided along the longitudinal axis of said container I by the half-discs I1 and I8 and the openings II in said cylinders 9. Said 55 discharge is thus prevented from changing its position suiilciently from the normal discharge path between said electrodes 2 to injuriously affect the walls of said container, so that a softer glass may be used in the walls of said container I than in a similar device in which the stringy" electric discharge is not guided. 'I'hellght emitted by the discharge is unobstructed in its passage through that side of container I opposite said half-discs I1 and I8.

The embodiment of the invention shown in Fig. 3 is in all respects similar to that shown in Figs. 1 and 2 with the exception that in this embodiment said half-discs I1 and I8 are arranged near the center of the discharge path between said electrodes 2 and are separated a distance less than the striking distance of the potential applied thereto. Said discs I1 and I8 are partly supported by a tube 2I of heat resisting, insulation material such as a glass or quartz tube. Lead wires 22 and 23 are arranged in said tube 2I and connect said discs I1 and I8 respectively, to one of the leads 3 of the electrodes 2, resistances 24 and 25 being provided in said leads 22 and 23 respectively. In this embodiment said discs I1 and I8 act as auxiliary electrodes and facilitate the starting of the main discharge between said electrodes 2 by ionizing the central portion of the discharge path during the starting of the device, and during this starting period a glow discharge takes place between said half-discs I1 and I8. 'I'his embodiment of the invention in other respects starts and operates in the manner described in conjunction with Figs. 1 and 2. The leads 22 and 23 are protected during the operation of the device by the quartz tube 2 I. Where desired, the resistances 24 and 25 can be located in the interior of the lamp unit.

In the embodiment of the invention illustrated in Figs. 4 and 5 the two half-discs I1 and I8 are arranged in the same plane perpendicular to the longitudinal axis of the container I of the device and are separated a distance less than the striking distance of the potential applied thereto.V

In this embodiment said discs I1 and I8 are supported entirely by the quartz tubes 2l and 2 I respectively. The inleads 22 and 23 for the halfdiscs I8 and I1, respectively, are located in said tubes 2|' and 2I. Saidtubes 2| and 2|' are supported in said container I by wires 26 and 28' respectively sealed into the stems 5. In this embodiment of the invention said half-discs I1 and I8 are free from the inner walls of said container I and the insulating, spacing rings 21 and 21', of porcelain, for example, located between said cylinders 9 and said support wires 26 and 28' serve to maintain said tubes 2|, 2l in position in said container I. The embodiment of the invention illustrated in Figures 4 and 5 is similar in operation to that illustrated in Fig. 3. The embodiment illustrated in Figs. 4 and 5 possesses the additional advantage that container I may be made as a straight sided tube without the discharge coming dangerously close to the walls of said container I.

It will be understood from the above description that the invention lends itself to a curved type of container, such as that shown in Fig. 6, in addition to the substantially straight type shown and described in the other gures. Referring to Fig. 6, the electrodes 2 are axially mounted in the ends of the container and the container consists of two substantially parallel tubes 8| and 82 with a curved tube portion 33 connecting said parallel tubes 3| and 82, half-disc I1, I8 or Il is arranged at the curved portion in said container along the discharge path in such manner that the stringy" electric discharge arc path extending from the electrodes 2 to the half-disc I1 or lll or from one half-disc I1 or 30 to another halfdisc I8 is not encroached upon by the walls of the container. The electric arc discharge between the electrodes 2 is thus prevented by the guiding half-discs I1, I8 and 30 from attaching to, or resting on a particular spot on the walls of said container and thus the container walls are protected from injury by the heat of the electric arc discharge between said electrodes 2. A softer, cheaper, and more easily workable glass, therefore, is used as the curved container of an electric discharge device having a stringy electric arc discharge than would be practical if the stringy electric discharge were not guided and controlled by the means set forth in this invention and the light emitted by the discharge is unobstructed in the direction away from said halfdiscs I1, I8 and 30.

While I have shown and described and have pointed out in the annexed claims certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:-

1. An electric discharge device comprising a container, thermionic electrodes sealed therein, a gaseous atmosphere thereimand a plurality of metal half-disks along the discharge path between said electrodes, said half-discs being transverse to the discharge path in said container.

2. An electric discharge device comprising a container, thermionic electrodes sealed therein, a gaseous atmosphere therein, said electrodes being surroundedgby a cylinder partially closed in the direction of the discharge path and a plurality of metal half-discs along the discharge path between said electrodes, said half-discs being transverse to the discharge path in said container.

3. An electric discharge device comprising a curved container, thermionic electrodes sealed therein, a gaseous atmosphere therein and a plurality of metal half-discs along the discharge path between said electrodes, said half-discs being transverse to the discharge path in said container and mounted at the curved part of said container between said electrodes.

4. An electric discharge device comprising a curved container, thermionic electrodes sealed therein, a gaseous atmosphere therein, and a lplurality of metal half-discs in said container, said electrodes being in the same plane, said container comprising two parallel portions perpendicular to the plane of said electrodes and a curved portion connecting said parallel portions, said half-discs being mounted along and transverse to the discharge path and at the curved portion in said container, the path of the electric discharge extending from the electrodes to the inner rims of the half-discs and from the inner rim of one half-disc to the inner rim of another half-disc thereby being spaced from the walls of said container.

5. An electric discharge device comprising a container, main discharge supporting electrodes sealed therein, a gaseous atmosphere therein, and a plurality of metal half-discs along the discharge path between said electrodes, said halidiscs being transverse to the discharge path in said container to guideY thehelectricdischarge between said main electrodes away from the Walls of said container and being connected through a resistance to said main electrodes to facilitate the starting of said device.

6. An electric discharge device comprising a container, main discharge supporting electrodes sealed therein, a gaseous atmosphere therein and a plurality of metal half-discs mounted in parallel planes along the discharge path between said main electrodes and transverse to the discharge path in said container to guide the electric discharge between said main electrodes away from the walls of said container, each of said half discs being connected to one of said main electrodes through a resistance and being separated from the other of said discs a distance such that the potential applied across said discs during the starting period is suicient to start an electric discharge therebetween to facilitate the starting of the main discharge between said main electrodes in said` device.

'1. An electric discharge device comprising a container, main discharge Vsupporting electrodes sealed therein, a gaseous atmosphere therein and a plurality of metal half-discs mounted in the same plane along the discharge path between said main electrodes and transverse to the discharge path in said container to guide the electric discharge between said main electrodes away from the walls of said container, each of said halfdiscs being connected to one of said main electrodes through a resistance and being separated from the other of said discs a distance suchI that the potential applied across said discs during the starting period is sumcient to start an electric discharge therebetween to facilitate the startinr of the main discharge between said main elec- KARL BECKER. 

